This invention is directed to a device that attaches to the bottom of ski boots for simulating ski movements. The devise is used for training and conditioning of skiers. The device has first and second sections each of which has a tapered surface of rotation as the bottom surface thereof. This allows for side to side rolling movements, front to back rolling movements and complex combinations of side to side and front to back rolling movements by users of the device.
Modern snow skis are flexible along their elongated axis. This allows the tip and the heel of the ski to flex with respect to the center of the ski. Further, such skis include hardened metal edges that bite into a snow or icy surface as a skier turns. In making a turn, as the metal edge of the ski bites into the snow surface both the toe and the heel of the ski naturally flex upwardly giving the ski an upwardly directed concave curve. This curvature of the ski causes the ski to turn or rotate.
In advanced skiing techniques, i.e. parallel skiing, the skier constantly weights one edge or the other of the skis putting more pressure on the weighted ski edge compared to the unweighted ski edge; however, the pressure on the weighted edge of the down-hill ski is different from the pressure on the weighted edge of the up-hill ski. This causes a natural rolling of the skier's ski boots and thus the skier's feet and legs located therein in a side to side manner. Because the pressure to the down-hill ski is different from the pressure to the up-hill ski, the amount of roll of one ski boot is not always the same as the amount of roll of the other ski boot. Further depending on particular maneuvers the skier is making, the advanced skier constantly weights and unweights his or hers skis as well as shifts his or hers weight on the skis either to the tips of the skis or the heel of the skis. This creates a forward or rearward rolling motion of the skier with respect to the ground.
Various prior training devices have been developed to assist a skier in learning to ski, improving skiing skills or in conditioning training. In order, however, to fully simulate skiing such training devices must allow for both side to side rolling motion and front to back rolling motion. Additionally, such training devices must allow for the individual movements of the right and left feet in an independent manner as is experienced in actual skiing.
An early training device described in U.S. Pat. No. 2,253,012 is essentially a pair of ski like slats that have been equipped with caster wheels. Such a training device would, of course, require a large smooth hard surface area for use thereon, as for instance, a smooth hill or the like. A similar type device is described in U.S. Pat. No. 3,622,172. In this device an elongated ski like structure is equipped with barrel like casters along its length. As with the previous device, this device also requires a large expanse of a smooth hard surface in order to be utilized. Such smooth hard surfaces are not soft and forgiving like a snow surface. Thus the users of these devices are subject to injury.
A further type of ski training device actually utilizes a pair of skis. The user secures the skis to his feet utilizing ski boots in a normal manner and then steps onto a platform that has the ability to rock side to side. This device is shown in U.S. Pat. No. 2,964,315. However, while the platform may rock side to side, the individual skis do not. As such the user does not get a full range of movement from this type of device. A similar type device is shown in U.S. Pat. No. 4,101,136. In this device the individual feet of the skiers can rock independently side to side. Further the device allows for the feet to slide fore and aft. However, this device does not provide for a fore and aft rolling motion that is naturally experienced during skiing because of the flexure of the ski.
A further training device is shown in U.S. Pat. No. 2,455,274. Because of the construction of this training device it is generally only useful for older, simplified skiing techniques, as for instance, teaching "stem-christies" and not more modern parallel skiing techniques. This device does not provide for individual rolling motion of the right and left feet independent of one another. An additional training device is shown in U.S. Pat. No. 3,729,207. This device allows for side to side movement and side to side rolling of the individual left and right feet, however common with certain of the above devices it does not allow for a fore, aft rolling that simulates flexure of the skis. A further training device is shown in U.S. Pat. No. 3,565,424 which again, while allowing for side to side rocking motion of the individual feet, does not simulate fore and aft rocking motion.
The exercise device of U.S. Pat. No. 4,251,068 allows for side to side rocking motion and in addition allows for rocking motion to the front around a rounded edge of the bottom of the device. The rear of this device, however, is squared off much like the transom of a boat and does not simulate the rearward rocking motion that is also encountered during skiing. And finally U.S. Pat. No. 3,612,520 shows a rounded disk like platform that can be utilized for exercising to build up the legs. In this device both feet are firmly planted on a non-movable surface and while the over all body is allowed to rock side to side and backward and forward, the individual feet of the user are not.